Horsepower calculator and recorder



J. N. G. NESBIT.

HORSE POWER CALCULATOR AND RECORDER. APPucATloN F1151) FEB. 17. 1915. RENEwD Dsc. 17.1921.

1.11. e. NEsw.

HORSE POWER CALCULATOR AND RECORDER. APPLICATION HLED FEB.17.1915. RENEWED DEC.17,1921.

l ,407,352, Patented Feb. 21, 1922.

m 5 SHEETS-SHEET 2. Qu e N J. N. G. NEsBxT. HORSE POWER CALCULATOR AND RECORDER.

APPLICATION FILED FEB. I?, 1915. RENEWED DEC. 17.1921.

1,407,352, Patented Feb. 21, 1922.

5 SHEETS*SHEET 3- TZ' .4. 75 5710 g J. N. G. NESBIT.

-HORSE POWER CALCULATOR AND RECORDER.'

APPLICATloN man 111.13.17. 191.5. RENEwED Dic. 11.1921.

1,407,352, Patented 111111.21, 1922.

5 SHEETS-SHEET 4.

1@ n MMM'. wfg/564% @gm W www J. N. G. NESBIT.

HORSE POWER CALCULATOR AND RECORDER.

. APPLICATION man FEB. 11. 1915. RENEwED Dec. 17.1921. 1,407,352.

Suunto@ WMM UNITED STATES PATENT OFFIC.

JOSEPH N. G. NESBIT, OF ATLANTA, GEORGIA.

HORSEPOTVER CALCULATOR AND RECORDER.

Application filed February 17, 1915, Serial No. 8,784. Renewed December 17, 1921.

To all whom t may concern:

tie it known that l, Josemi N. G. Nnsnrr, a citizen of the United States, residing at Atlanta, in the county of Fulton and State of Georgia, have invented certain new and useful improvements in Horsepower Calculators and Recorders, of which the following is a specif cation.

This invention relates to a machine for mechanically determining the horse-power ot prime movers and for indicating the horse-powers determined thereby.

As is well known to those versed in engineering, indicators have been long in use in connection with steam engines and other.

prime movers for graphically illustrating the expansion ot steam or other motive fluid by means of an auxiliary cylinder attached at some appropriate point to the main steam or power cylinder permittingy the force ot expansion of the motive fluid to act against a light-moving piston to force the same against a delicate and accurately gaged spring whereby a light parallel-motion device is operated to mark the lines of pressure by a ipencil on paper moved to and tro by a second cylinder which is actuated by the motion of the main piston Within the enginecylinder.

The indicator cards produced by this apparatus permit the horse-power of the engine to be determined from the area of the cards by the usual formula:

H l P L A N orse-poWer equa s 33,000 1 W here P equals the mean effective pressure in square inches; L, the length of stroke in feet; A, the area of cylinder in square inches; and N, the number of strokes or revolutions er minute. The mean effective pressure, is usually obtained by multiplying the scale of the spring by the quotient given by the area of the card as divided by the length of the card.

lt vill be well remembered by those accustomed t0 this calculation that an accurate determination of the horse-power demands particular measurements of the engine and the determination of the indicator card area by means of a planimeter or other device of a like nature as Well as involving tedious calculations.

It is accordingly contemplated by this invention to substitute for the above described mental and manual processes, means me- Specication of Letters Patent.

Patented Feb. 21, 1922.

serial No. 523,244.

chanically effecting the desired result by a suitable automatic mechanism.

It is a further object to provide an automatic horse-power indicator of the type above described capable of. application without material change to either condensing or non-condensing engines in which steam is the motive fluid, or in prime movers or" other types and t0 indicate upon a suitable cloe;v dial the horse-power for any given instant and to preserve a continuous record for the performance of the engine to which this mechanism may be attached, for any given period of time.

Objects of a more specific nature, but particularly allied to an invention including the above mentioned means, are to provide in connection with the indicator piston and spring of a customary variety, means mechanically multiplying the ordinates of pressure by what is termed the engine constant; means mechanically adding each such multiplication, et which there are a plurality for each stroke of the engine and means establishing electrical connections for recording the total as summed by the precedingmeans once for every revolution ot the engine.

rlhe above and additional objects which will become apparent as this explanatory description proceeds are accomplished by such means as are illustrated in the accompanying` drawings, described in the following specification, and then more particularly pointed out in the claims which are appended hereto and form a part of this application.

With reference to the drawings, wherein there is illustrated the preferred embodiment of this invention as it is reduced to practice, and throughout the several views of which like characters of `reference designate similar parts:

Figure l is a side elevational idew of an arrangement of the means comprehended by this invention and acconnolishing the objects thereof,

Figure 2 is an enlarged detail of a portion of Figure l,

Figure 3 is a sectional view on the line 3-3 of Figure 2,

Figure l is also an enlarged detail of matter illustrated in Figure l, parts being severally broken away,

Figures 5, 6 and (5il are details of the shiftable means broken away in Figure il,

Figure 7 is also an enlarged view o a portion of Figure 1, showing in detail the electrical recording connections,

Figures 8 and 9 similarly are views in detail of portions of Figure 7 Figure 10 is a transverse sectional view on the line 10-10 of Figure 4, looking in the direction indicated by the arrow, and

Figures 11 and 12 are diagrammatic views of indicator cards for non-conde-nsing and condensing engines respe'ctively.

The basic idea of this invention depends upon a mechanical determination of the average ordinate of the indicator card as given by the expansion of the steam against the usual indicator piston and spring. Assuming that one such card such as illustrated in Figure 11 for a non-condensing engine is vertically subdivided by the ordinates a-a, b-b, 0 0', etc., it will be apparent that these ordinates will be given respectively and successively from the line ot' steam admission A to the exhaust point B if the indicator piston is permitted to rei the atmospheric pressure) before permitting the admitted steam enclosed in the engine cylinder by the cut off to expand from this abnormal compression along the line of' the next following ordinate.

It should be apparent that the course ot' the indicator piston as the steam is alternately permitted to expand in its normal manner, in producing the customary lessening curve from lo to a', or is compressed; will be along the expansion line A upwardly, returning to the point 7c by the dotted line in the compression stroke of the pist-on, then upward against the first o rdinate of expansion k-c and so alternately downwardly by means of the dotted lines and upwardly on the ordinates of expansion. Mechanical means as will be hereinafter more fully described successively add these upward strokes by intermittently moving a common reciprocating bar so that the sum of such strokes may be ascertained, the average being found by reading the said sum to a one-tenth (-11,5) scale since it is proposed to provide some ten (10) ordinates or' expansion :tor each movement of the engine piston in one direction by affording ten (10) abnormal compression strokes along thev above mentioned dotted lines to the indicator piston. Of course, it is to'be understood that any number of ordinates may be provided for calculation purposes.

By providing means geared to the engine shaft at a ratio of 2 to 1 or any other suitable ratio, it will of course be possible to provide for the registering of a number of ordinates on each half stroke of the engine, those on the forward stroke being as already described from the atmospheric line a-c to the expansion curve a-c while those on the return .stroke of the engine will be from the atmospheric line af-c to the exhaust line t2- b2 which latter is connected with the expansion curve when the exhaust ports are opened as at B. In the case of the non-condensing engine these ordinates registered by the mechanism are of course to be subtracted from the ordinates given on the forward stroke in order to give the effective pressure, the mean of which is found as already described. In the case of the condensing engine the card of which is illustrated in Figure 12 the ordinates /,-/L'^", b--b2, @-02, etc., are to be added to the first set of ordinates c-c, vl-f/I, t-t, etc., since in the case of engines of the latter character the exhaust is below the atmospheric pressure which must be included in the mean effective pressure.

It will be obvious from the foregoing that with the mean effective pressure thus determined to take the place of P in the PLAN th t t `ll b 337000, a 1 W1 e necessary to multiply this P both by the constant for the engine (the product of the length of the stroke by the area of the piston as divided by 38,000) and by the number ot revolutions in order to obtain the horse-power for that given number of revolutions. Means mechanically effecting this multiplication are to be hereinafter disclosed so that the theory of this invention may be stated to multiply each ordinate of pressure in sucformula cession by and to add these successive products upon a bar which may be read to one-tenth (6) of the acquired sum in order to properly average the ordinates. This addition of ordinates 7th-k', t", L-h, etc., is taken in one direction of the adding bar for the forward stroke of the engine while upon the return stroke ot the engine there will be either subtracted or added (depending upon the noncondensing or condensing character of the engine) the ordinates tha b-bz, 0 02, etc., resulting in a further movement of the bar in one or the other direction and thereby accurately permitting the positioning 0f a pointer carried by the bar so that suitable electrical connections can be made against every stroke of the engine to record the final position.

Referring more particularly to the actual construction involved in a reduction ot' means accomplishing these theoretical purposes to practice, the numeral 15 designates a suitable traming including side bars and cross rods in which may be supported in any suitable manner with which this invention need not be particularly concerned, a shaft 16 adapted to be driven at the same rate et speed as the engine shaft, and in some instances of stationary engines may be the engine shaft itself. A gear l? is moimted upon this shaft for engagement with the smaller gear i8 carried upon a stub shalt i9 parallel with the shaft 16 and carrying; al e the large gear 20 Whiei meshes with nears 2l carried on stub shafts 22 suitably mount ed in the framing l5 and f tremities. The mentioned gears serve the purpose ot effecting a rat-io revolution between the disks 23 and shan; 16 of 2 to l live to one or any other suitable ratio so that means connected these disks and revoluble therewith may operate once or two and one-halt times to each halic stroke of the engine as will be necessitated When desirably operating' the ordinates.

A bar 24 is mounted in suitable horizontal members of the framing l5 for vertical reciprocation therethrough, such bar being` connected as clearly shown in Figure i, With a piston rod 25 around which is placed the light and accurately gagcd indicator spring 26 for acting upon the piston head 27, against the under tace ot Which latter, steam is adapted to exert its expandin:g force when admitted through the nozzle 28, as the indicator casing 29, housing the orementioned elements is connected L means 30 to the Working cylinder ot the steam engine to which the apparatus coinprehended by this invention is attached. lt may here be remarked that the preterred embodiment ot the horse-power indicator and recorder of this invention is to be d` closed in connection with its apjlieabil to steam engines, but it will be apparent that Within the scope of this invention lie the adaptational means rendering this cator and recorder applicable to une movers in which some other motivo tluid than steam is employed.

Slidable upon the ordinate rod 2i but independently thereoi`l are the cross heads ill oppositely connected by cranks to the previously mentioned disks and like them adapted to make a complete reciprocation two or tive times as the case may be to ea' h complete revolution of the shaft 16. rl` l `se cross heads are used as a rese ing means for the ordinate rod 2l and control movement ot the same by means ot pins El?) against Which the cross heads contact in the manner to be hereinatter more tully set forth, these pins being on opposite sides oil the center or" the rod trom a locking pin 34- positioned at such center.

Horizontally slidable through brackets 35 secured to one of the upright plates otl the Jframing l5 is the rectangular carriage 36 iiri-ned at one extremity with an offset surface 37 adapted to coact with cams 38 or 39 carried by the disk 440 mounted on the main shaft 16 and rotating therewith as does also the cross head il connected by crank means Lll2 to the said disk 40. Upon the other extremity of the carriage 36 are resiliently mounted as at 43, a pair ol triangular locking plates fil- Which are normally maintained out ot engagement with their reacting pin "le" by means of a central expansible spring o acting against one ot the mounting` brackets 35 in order to with- ,W the plates eel trom a position ot locking engagement with their pin until the carriage is actuated by one ot the cams 3S or "39 against the tension ot the spring to momentarily so lock the pin let and consce quently the' ordinate bar lt Will be ob vious that such locking engagement is adapted to occur once at every halt revolution ot tie shaft 16 owing to the diametrically opposed positions oil the actuating cams, the release edges ot which are alined with the crank l2 when the latter is occupying its dead center position.

iis brought out in the preliminary/,fY discussiom vertical movements ot the bar 2li correspond graphically to the proper effec tive pressure which must be multiplied by the length oit stroke ot the engine, the area of the piston and the number ot such strokes per minute, the whole product to be divided by 38,000. Since it is aimed to etlect these operations of multiplication and division by mechanical means includingl variably tulcrumed` levers, it will be apparent that the engine constant should iirst bo re- L A 33,000 duced to decimals in order to more readily provide a single factor to shorten these operations. Since this decimal is trequently in the ten-thousandths and since the numbei' ot revolutions oi the engine, the other factor. is reversely, a large number, means have been provided. whereby a cancellation of these two oppositely large numbers may be effected mechanically as will be more fully set forth in the operation to follow.

Pivotally connected at Li6 to the uppermost extremity of the bar 2d is a slotted link fl? in the slot ot Which is movable a variable tulcruming point i8 of any obvious construction for shittable arrangement with regard to the supporting` plate e9. vertical link Fn transmits movement ot the outer extremity oi this bar 41T to a similarly slotted link 5l which is tulcrumed upon a pin 52 of a bell crankl, such pin also working in a. slot 54 ot a bracket 55 also secured to the supporting base 4:9 in order to maintain the i'iulcruming` pin 52 in the adjusted position determined by the bell crank 53. This latter has its angled extremity also slotted to receive the pin 56 slidable therein and carried by the sleeve 57 of a lgoverningdevice denoted mainly by the numeral 5S,

llO

such device beingh provided with the usual balls 59, the movement of which determines the shitting ot' the bell crank 53 which is suitably pivoted as at 60.

The tree end oiC the slotted link 51 is vertically and pivotally connected by means 61 to a T-bar 62, this latter being pivoted as at 63 to a 'framing 6e and havingthe vertical terminals of the T-portion pivoted by linl'; connections 653 to horizontally slidable bars which attuate in the manner clearly shown in Figure 4r., parvis respectively designated by the numerals 67, 68, and 69 to; operation upon a bar '4" 0 provided interina diately with suitable rack teeth '71 arranged on both edaes for a portion ot' the bar length and inclined in one direction for Operation thereupon by the paivls 67 and 69, While also arranged upon a portion ot the bar spaced. from the first said portion are oppositely in clined teeth 72 with which 'the pawl 68 adapted to coact as will be presently set forth.

Since, as has been explained in connection With the previously presented theory ot this invention each ordinate given by the expansion of the steam against the indicator pis-- ton is registered upon the rack bar, which serves to successively add such ordinates, such piston must again be pressed to its normal position as regards the atmospheric line ot the expansion cards, betere permitting' the next ordinate of expansion to be registered upon the adding bar, so that some means must be provided to prevent the engagement of the paivls With this adding bar at certain times. This means includes stirrups 73 which are operable by a pair ot shitting` devices 74; and 75 as illustrated respectively in Figures 5 and 6. This latter device is in the nature ot a gate having the parallel members 7 6 oppositely shittable by means ot' a lever 77 pivoted to each bar at 78 and intermediately ulcrumed as at 79 upon a stationary bar 80 which is secured to the tivo vertical framing pieces 81 against which the parallel bars 7 6 are slidable. Each ot these mentioned bars Y6-carries one ot the stirrups 73 and the Whole device is positioned adjacent the rack bar 70 in t-he manner clearly illustrated in Figure 10 so that the bars carrying the L-shaped stirrups may be interposed betyveen the rack and the various paivls at certain desirable periods in the operation ot' the device by a longitudinal and shitting motion with respect to such bar 70. The pivotal and fulcrum points ot the lever v77 are seated in suitable slots 82 in order to provide for a necessary up and'doivn movement ot this lever Without vertically actuating the sliding gate 7 5, as will be hereinafter more fully explained. 1t desired the stirrups may be iXedly secured to the framing' 64 and of such sizes that the various paivls will be disengaged thereby With the rack 70 according` to the angular movement of the bar 62.

The shittingdevice 711 as illustrated in Figure 5 is seen to include the body plate 83 suspended from the 'trame members 64 by suitable parallel pivoting links Se and being; adapted to be actuated by the similarly pivoted lever 65 through the short link 86, said lever having link connections 8T with a second verti il lever pivoted as indicated at 69 to a si -able portion of the trame 15 and extending belon7 such pivotingr point tor a contacting` relationship with the extensions 90 and 91 ot the cross head l1 operative in conjunction with the engine sha'lt 16. Pins 73 are carried by this plate 74 tor operation in suitable slots ot the stirrups 7&3 so that the movement ot these latter can be controlled by either of said shittingv devices, both being' used for separate purposes.

The adding bar 'T0 is prolonged at each extremity to allow for the proper movements ot addition and subtraction and carries adjacent one ot these produced extremities an arm 92 mounted on suitable insulation 03 spacing` the same trom the bar and carrying at its head the metallic indicator point or tracing pencil 9st directed towards a dial 95 Which as illustrated may be a rotatable clock dial provided with cross sectioned or indicator paper and which is supported concentrically with the solenoid 96. Electrical current for the proper actuation oi the solenoid is supplied by a suitable source ot difference ot potential 97 through the conductors 9S and 9S) forming a circuit including the said solenoid, one oi' said conductors being connected to the :trame 15 as indicated at 100; the other ot said conductors having electrical connection to a suitable point ot contact 101 insulated from the said trame and stationary thereupon. A. movable Contact 102 adapted to automatically make connections with the said stationary contact is carried by the connecting` rod 4t2 ot the cross head 4:1 and at such a distance from the pivot of said connecting` rod as to have a movement of Which there is some small vertical component so that connection will be established bctWeen these contacts but once every revolution oit the shaft 16 to close the circuit and actuate the solenoid 96 once for each ot these revolutions as will be readily apparent from the dotted line showing ot Figure 7, the movable contact missing contact 101 on the tor- Ward stroke and beingr just permitted to make connection at the completion of the return stroke of the connecting rod.

The cross head 41 carries as has been mentioned the extensions 90 and 91 the former actuating the lever 88. The extension 91 is enlarged to contact with the short end of a lever 103, the opposite extremity of which is slotted to loosely receive a pin 106 carried by a sleeve firmly secured to the adding bar for which this lever acts as a resetting means once upon every revolution of the said connecting rod 112. ft should be noticed that as illustrated in kFigures 1 and T the contact 102 has passed the stationffiry Contact when the extension 91 is in contact with this lever so it will be apparent that means are afforded for recording the position of the pointer 92 upon the dial before the 'adding bar carrying such pointer is reset to the line denoting atmospheric pressure.

The complete operation of the device may be set forth briefly as follows:

The casing 29 is connected with the working cylinder of the engine and steam from such cylinder is admitted in the usual manner toact against the piston 27 in order to actuate the bar 24; in the manner already mentioned. If We consider that the value of S-g), the engine constant, to be some such quantity as .0135 and that the speed of the engine as indicated by the governor 53 is say,l for example 100 revolution per minute. it will be remembered that it is necessary to cancel from each of these two factors, such common divisors as will enable us to represent quantities for each of these factors in the general multiplication such that they may be easily determined to scale.l when set upon the various multiplying` lever arms. To do this in the given case above cited the engine constant is multiplied by 100 so that it may be written as 1.35 and this factor of 100` is removed from the number of revolutions leaving this latter now 1 so that the product of the factors J-goig is in either caseof this given example, 1.35, as a multiplier for the mean effective pressure determined by the rod 24, both of the new numbers being much easier to set out on the levers. When the speed of the governor 5S is 100;` revolutions, the pin 52 is adapted to assume that position with the slot 511- such that movement of the right hand end of thev bar 51 will be trebled upon the upright (S1. Similarly, the fulcruming point l-S is to be shifted within the slotted link l17 and it is apparent that a scale may be used in con.- junction With such point to enable itvto be accurately set to the needed quantity such that the right hand end will multiply any force exerted by upward movement of the rod 24 by the factor 1.35 so that the whole movement of such rod will be multiplied upon the rod 61 by The 'driving gears 17 and 18 provide for one "reciprocation of the shaft 2%. for each half the atmosphere line of the card after every displacement. Steam first admitted into the casing 29 forces the piston 27 upward on the usual admission line A of Figures 11 and 12 T and such ordinate is multiplied by in 70 he manner above set forth as regards the imulse thereby given to the bar 61 which in irn actu ates the T-bar 62 through the angle as illustrated in Figure 4, exerting a pull .pon the upper bar 66 such that pawls 6T and 8 do not engage with the rack, and exrting` an equal push upon the lower bar G6 o drive the pawl 69 into contact with the rar 70 and to force this adding bar forward 80 a distance commensurate withl the said impulse. it being noted that leaf springs are thereby provided for each pawl to normally insure contact therebetween and the rod unless otherwise decreed by the position of the stirrups 73. Immediately after this initial admission impulse has been thus reported. the upper cross head 31 returns the bar 241- to its original position and again permits the steam compressed by this return movement to expand along the ordinate ,tw/v and this result is repeated throughout the entire diminishing expansion effect of the steam during 1 revolution of the disks 23, or during one half revolution of the engine shaft 16.

Atthe completion of the first half revolution of this shaft the cam 39 has come in contact with the shiftable catch plate 36 and in the obvious manner has permitted the catches Ltlto engage thel locking pin 34 so 100 that the bar 24: is held stationary. This cam also operates againstthe lever 77 to shift the paw] actuating device 75. so that before the return stroke of the engine corresponding to the exhaust line of the indicator cards. all of the pawls will be thrown out of engagement with the rack, although this condition merely lasts long enough, as determined by the action of a suitable spring 77a as illustrated in Figure 1 to permit the v110 passage of the cam 39, such spring drawing the bar 77 back to its original position. `While this movement of the pawl shifter 75 serves no purpose at the end of the first half revolution of the engine shift, it is necessary at the completion of the entire revolution vfor the reason that the bar 70 must be reset and all the .pawls, accordingly, must be disengaged therewith. The bar 7 7 which is thus interposed `in the path of the cams for actuation thereby at the completion of one revolution must necessarily be also actuated at every halfrevolution although at this latter time its working neither adds nor detracts from the proper operation of the machine. n n

The pawl shifter 74 While occupying the position illustrated in Figures 1 and et for the first half revolution of the engine shaft is new deected by the enlarged portion 91 130 of the cross head 4:1 to occupy the dotted line position illustrated in the latter figure so that the stirrups 73 are shifted from right to left of this figure in permitting pawl 68 to aetuate the rack and pawls 67 and 69 to be inoperative thereupon during the return stroke of the engine, the rod 61 still transmitting impulses of the multiplying mechanism and steam expansion to the T-bar 62 'through the angle a. It will be apparent that the motion thus given by the pawl 68 to the adding bar is a motion of subtraction from the amount formerly totaled by the expansion ordinates in order to arrive at the true determination of the actual power ordinates of the. engine. The immediately preceding description is true, of course, only in the case of a non-condensing engine which operates the T-bar always through the angle a. In the case of a condensing engine the exhaust is below the line of atmospheric pressure, here corresponding to the vertical line bisecting the combined angles a plus of Figure 4, and, accordingly the bar 61 is downwardly actuated upon the return stroke of such an engine moving the T-bar through the angle b thus affording a push and pull to the upper and lower` bars 66 respectively and thus permitting the pawl 67 to add upon the bar 70 thenew amounts in place of subtracting them therefrom.

The process of algebraically adding the exhaust strokes is continued through a like number of ordinates as characterized in the primary addition upon the bar 7 O and at the completion of the engines return stroke, contact is made as previously mentioned between the respectively fixed and movable contacts 101 and 10Ql so that the circuit is closed to actuate the solenoid 96 whereby the final position of the pointer 94 carried by the adding bar is recorded upon the clock dial face 95. Since this latter revolves and is covered with a suitable cross section paper, it is readily apparent that a graphical illustration may bemade for a continuous run of the engine as is indicated by the broken line shown upon this clock dial face in Figures 1 and 7. the pointer 94 normally occupying a position` opposite the center of the dial before primary actuation of the bar and being reset to this position by the previously described lever 103 controlled by the cross head enlargement 91 at the completion of the engine stroke.

From the foregoing, it should therefore be apparent that means have been disclosed whereby the objects previously presented are capable of being accomplished, so that this invention may therefore be claimed as possessing the advantages and desirability set forth insuch objects.

Vhile in the foregoing however, there has thus been illustrated in the drawings, and described in the specification such combination and arrangement of elements as constitute the preferred embodiment of this invention, it is desired to emphasize the fact that such minor changes in the matters of proportion and degree may be made in later adaptations of this device as shall not alter the spirit of the invention as defined in the appended claims.

That is claimed is 1. Means, in combination with an indicator-piston rod for prime movers, adapted to multiply movement of said piston rod by the engine constant and the number of revolutions per minute of said prime mover, in mechanically determining the horse-power of said prime mover, and pawl and rack means for the addition or subtraction of the complete strokes of said piston.

2. Means, in combination with the indicator-piston rod of a prime mover, adapted to multiply movement of said piston rod by the engine constant and the number of revolutions per minute of said prime mover, of means both manually and automatically actuated, for adjusting the multiplying means in mechanically determining the horse-power of the prime mover, and pawl and rackvmeans for the addition or subtraction of the strokes of said piston rod.

3. Means, in combination with the indicator-piston of a. prime mover, for multiplying movement of said piston by the engine constant and the number of revolutions per minute of said prime mover, of means for arranging the said first means to cancel out opposed factors in said multiplier in more easily determining mechanically the horse-power of the prime mover, and pawl and rack means for the mechanical addition or subtraction of the strokes of said pistonrod.

4l.. Means, in combination with the indicator piston of a prime mover, adapted to multiply movement of said piston by the engine constant and by the number of revolutions per minute of said prime mover, of means for canceling out from said multipli ers opposed factors in facilitating the multiplying process, means for adjusting the first said means to suit varying conditions when mechanically ('letermining the horse-power of prime movers, and pawl and rack means for adding or subtracting the strokes of said piston.

cator piston for a prime mover, adapted to multiply the ordinates oit expansion o'j the motive iiuid ot said prime mover by the engine constant and by the number olf lutions per minute or said prime a pavvl and rack mechanism tor the i dition or sijibstraction ot sait. oroinatef' and means for adjusting said first mean@`v in mechanically determining the horsepower of the 1prime mover.

7. Means, in combination with the indicator piston of a prime mover, 'for multiplying the ordinates of expansion ol die motive fluid ot said prime mover by the engine constant and the number ot revolutions per minute of said prime mover, means i'for automatically adding or subtracting said ordinates, and means for arranging said irst means to cancel out opposed factors in said multiplier in more easily determining, mechanically, the horse-power oi" the prime mover.

8. Means, in combination Withthe indiator piston ot a prime mover, tor multiplying successive ordinates or' expansion ot the motive fluid of said prime mover by the engine constant and the number ot' revolutions per minute ot said prime mover, means for automatically adding or subtracting mechanically the said ordinates, means for canceling equal opposed factors in -facilitating the multiplying process, and means for adjusting the' said lirst means when mechanically determining the horse-power of the rime mover.

9. l/ieans, in combination With the indicator piston ot a prime mover, for multiplying successive ordinatesv ot eXpa-nsion ot the motive fluid ot said prime mover by the engine constant and the number of revolutions per minute or the prime mover longitudinally movable means for the addition or subtraction oli said ordinates, and means lor recomprcssing said motive fluid through direct operation of said piston to obtain a reexpansion ot the former 'ji-om the start.; g point when mechanically determining the horse-power ot the said prime mover.

l0. Means, in combination with indicator piston ot a prime mover, tor nuiltiplying successive ordinates ot expansion of tl e motive fluid ot said prime mover by the engine constant and the number oi" revolutions per minute of the prime mover, a

' longitudinallj,7 movable member', connections between the latter and said indi-catorpiston to operate said member and ad/l or subtract said ordinates, rieans for recompressing said motive fluid through direct operation ot said pistonto obtain a reexpansion oi: said fluid from the point ot atu'lospheric pressure, and means for adjusting the said tirst means in mechanically determining the horse-newer ot the prime mover.

ll. ll/ieans, in combination with the indicator piston oi a prime mover, for multiplying successive ordinates of expansion ol the motive fiuid by the engine constant and he nuu'iber ol revolutions per minute, a rare: bar. connections betvveen said rack bar und the iston to mechanically operite the 'mer tor the addition or subtraction it said ordinates, means for recompressing said motive tluid to obtain a reexpansion thereoii from the point or atmosphe ic pressure, and means llc-r arranging lirst said means to cancel out opposed factors in said multipliers in more readily determining, mechanically, the horse-power ot the prime mover.

l2. Means, in combination ,v'th the indicator piston et' a prime mover, for multiplying successi ordinates of expansion or the motive 'Huid by the engine constant and the number ot revolutions per minute, a pawl and raclr mechanism operable in either direction, means tor operating said mechanism from said indicator-piston 'for the addition or subtraction ot said ordinato., means 'for recompressing said motive Huid to obtain further expansion ordinates, means for canreling equal opposed factors in facilitating the multiplying process, and means tor adjusting the lirst said means in varying the multiplying process When mechanically determining the horse-power ot' the prime mover.

13. lleans, in combination with the indicator piston oil: a prime mover, for multiplying successive ordinates oit expansion o't the motive fluid oi" said prime mover by the engine constant and the number of revolutions per minute, racl: means for the addition ot' said successive ordinates, and paivls operative upon said rack means to add the ordinat-es or subtract the same thereupon.

lll lli/leans, in combination with tho indifxator piston ot a prime mover, tor multiplying succ ssive ordinates ot expansion o'lt the motive Afluid for said prime mover by the engine constant and the number ot revolutions per minute. means for recompressing` said motive fluid to obtain a plurality of further expansion ordinates to each halt revolution et said prime mover, rack means for the addition ot said ordinates, and pawls operative upon said rack to add the ordinatos or subtract the same thereupon according to the particular hallc revolution and the character oV prime mover.

l5. lilcans, in combination with the indicator piston ot a prime mover, ttor multiplvincv successive ordinates ot expansion ot the motive fluid ttor said prime mover by the Yng constant' and the number ot revolutions por mimiteq means 'for rccomprcssing said fluid to obtain a plurality ot 'further expansion ordinates to each halt revolution ot prime mover, rack means for the addition o said ordinates, paWls operative upon said rack to control movement of the same with regard to said successive multiplied products, and means for reading the final position of said rack to a scale having the ratio of unity to the number representing` the said plurality of further expansion ordinates.

1G. Means, in combination ivith the indicator piston oi a prime mover, for multiplying successive ordinates of expansion of the motive fluid for said prime mover by the engine constant and the number of revolutions per minute, means for recoinpressing said motive fluid to obtain a plurality of further expansion ordinates to each halt revolution of said prime mover, rack means, paivls operable thereupon to record such products thereupon, an indicator arm carried by said rack, a pointer carried by said arm, and means for recording the position of said arm by means of said pointer at the completion of each revolution of said prime mover.

17. Means, in combination with the indicator piston of a prime mover, for multiplyini,v successive ordinates of expansion of the motive fluid for said prime mover by the engine constant and the number of revolutions per minute, means for recompressinp,f said motive fluid to obtain a plurality7 of further expansion ordinates to each half revolution of said prime mover, raclr means, pawls operable upon said rack to record the products thereupon, an indicator arm carried by said rack, a pointer on said arm, means recording the final position of said pointer at the completion of each revolution of said prime mover, and means for resetting said rack immediately after the recording process.

18. Means, in combination with the indicator piston of a prime mover, for multiplying successive ordinates of expansion of the motive fluid of said prime mover by the engine constant and the number of revolutions per minute, means for recompressing said motive fiuid to obtain further expansion ordinates, rack means, payvls normally operable upon said means, pavvl shifting devices, stirrups carried thereby to interpose between said paivls in turn and said rack in permitting' certain paivls only to operate upon the latter in recording thereupon the said products according to the particular half revolution and the character of prime mover, and means for resetting such rack,

19. Means, in combination with the indicator piston of a prime mover, for multiplying successive ordinates of expansion of the motive fluid of said prime mover by the engine constant and the number of revolutions per minute, means for recompressing said motive fluid to obtain further expansion ordinates, rack means, pavvls normally operable upon said rack, paWl shifting devices, stirrups carried by said devices to interpose between said paivls and said rack in permitting certain paivls only to actuate said rack to record thereupon the said products, and pivoted l vers connected to said devices and operable by uncts of the prime mover at each half revolution of the latter.

20. Means, in combination with the indicator piston of' a prime mover, for multiplying` successive ordinates of expansion of the motive fluid of said prime mover by the engine constant and the number of revolutions per minute, means ior reeompressing,r said motive fiuid to obtain a pluralityv of further expansion ordinates, rack means, panfls engageable vfith said rack, means operatively connecting said paivls with said multiplying` means to drive said rack in accordance With the products of the latter, indicator means carried by said rack, shiftable means operable by movable adjuncts of the prime mover to direct the actions oil certain of said pawls at a time, a revolving dial face for use in conjunction with said indicator, an electric circuit, means operable by said movable adjuncts to close said circuit at the completion oi each it'ull revolution of said prime mover to note the final position of said indicator `with respect to said dial, and neans for resetting said rack after each determination of the horse-power.

21. Means, in combination with the indiiator-piston and main shaft oit the prime mover, for multiplying successive ordinates oi expansion of the motive fluid for said prime mover by the engine constant and the number of revolutions per minute, means for recompressingsaid motive fluid to obtain a plurality of further expansion ordinates to each half revolution of said prime mover, rack means, parvls operable thereupon to record such products thereon, an indicator arm carried by said rack a pointer carried by said arm, means for recording the position of said arm by means of said pointer at the completion of each revolution of said prime mover, means controlled by said main shaft to throw said paivls to inoperative position, and means to return said rack means to normal position.

22. Means, in combination with the indicator-piston and main shaft of a prime mover, for multiplying' successive ordinates of expansion of the motive fiuid for said prima mover by the engine constant and the number of revolutions per minute, means for recompressing said motive fluid to obtain a plurality of' further expansion ordinates to each half revolution of said prime mover, a longitudinally movable member for the addition of said ordinates, mechanism operative upon said member to cause a step by step movement of the same and thereby add the ordinates or subtract the same thereupon according to the particular half revolution and the character of prime mover, means for automatically moving said mechanism to inoperative position at the completion of eac-h half revolution of said prime mover, and means controlled by said main shaft to return said member to normal position at the end of each complete revolution of said prime mover.

23. Means, in combination with the indi- Gator-piston and main shaft of a prime mover, for multiplying successive ordinates of expansion of the motive fluid for said .prime mover by the engine constant and the number of revolutions per minute, means for recompressing said motive fluid to obtain a plurality of further expansion ordinates to each half revolution of said prime mover, means for momentarily locking said piston in normal position at the end of each half revolution of said main shaft, a longitudinally movable member, means for operating said member according to movement of said piston to add or subtract said ordinates of expansion of the motive liuid, means controlled by said main shaft for moving the last mentioned means to inoperative position at times, means for recording the position of said longitudinally movable member, and means controlled by said main shaft for returning said longitudinally member to normal position when released at the end of each revolution of said prime mover.

In testimony Whereoitl l afiix my signature in presence of tivo witnesses.

JOSEPH N. G. NESBIT.

`Witnesses1 J. H. SCHROEDER, T. L. JOHNSON. 

